Free discharge valve



April 26, 1955 R. BAccHl 2, 706,996 EREE DISCHARGE VALVE Filed Nov. 9, 1951 2 Sheets-Sheet l #fram/fr R. BACCHI FREE DISCHARGE VALVE April 26, 1955 Filed Nov. 9, 1951 2 Sheets-Sheet 2 IN VEN TOR. 424V mc/w 2,706,996 FREE DISCHARGE VALVE Ray Eacchi, Daly City, Cali assignor to The Pelton Water Wheel Company, San Francisco, Calif., a corporation of California Application November 9, 1951, Serial No. 255,718 4 Claims. (Cl. 137-219) nism operating positively and well under extreme and adverse conditions. The size of the valves is usually so large that the design must take into account various h ydraulic phenomena that are not particularly noticeable in small size valves.

It is therefore an object of my invention to provide a free discharge valve effective to control the quantity of flow from a conduit into the object of my invention is discharge valve including suitable structure for opening and closing the valve positively under operating conditions.

A still further object of my invention is to provide a free discharge valve in which the water flow through the valve is of a satisfactory nature.

A still further object of the invention is to provide a free discharge valve which can be closly regulated to improve free discharge valves.

Other objects, together with the foregoing, tained in the embodiment of the accompanying description companying drawings in which:

Figure l, in the lower half, is a side elevation in open valve, portions being broken away to reduce the size of the ligure.

Figure 2 is a View comparable to Figure l but showing the free discharge valve in closed position.

Figure 3 is a fragmentary end elevation supporting rail and attendant nection with the discharge bell.

showing a structure utilized in coning studs 19. At appropriate points on its exterior, the

32 adjacent the lip 41 one or more, of symmetrically disposed rails 42 aligned in the general direction of the discharge bell. These rails are designed to operate between flanged wheels spite its large size and great weight.

Pursuant to my invention, I provide means for utilizing the discharge bell for controlling and secured together. is provided with Wear-resistant of the discharge bell. The area for fluid flow is maintained substantially constant but, even so, offers some resistance. Additionally, me baille around its outermost portion is provided with a wearresistant ring diffusing bell bell.

When the diffusing bell 32 51 in its extreme position. surface of the diffusing bell S6 also diverging outwardly :toward the and disposed in the path of travel of the 51. The diameter of the two abutting annular seats is greater than the diameter of the conduit 16 and also is greater than the diameter of the outside of the bearing 28. Preferably, the seats 57 and S8 are fabricated of separate pieces of wear-resistant metal, although the seats can be simply specialized areas on the discharge bell and on the bale itself.

The contour surfaces extending from the abutted seats 57 and 53 on the upstream side of the conduit 16 are entirely open to hydraulic liquid under pressure. The seats 57 and 58, whether separate parts or not, are the only parts of the discharge bell and of the baille which come into physical contactto prevent liquid flow.

In accordance with my invention, l provide means for moving the discharge bell between the cxtreme left hand position of Figure l and the extreme right hand position of Figure 2 under power. Preferably the pressure difference existing between the pressure liquid within the pipe 6 and the atmosphere is utilized for this purpose. Accordingly, with a boss 61 serving as an inlet mount for a pipe 62 having a section 63 leading into the chamber 26 and having a control valve 64 interposed in it. When the control valve 64 is in open position or nearly open position, liquid within the pipe 6 and in the transition section is free to flow into the chamber 26. lt exerts its full pressure against the upstream face of the piston 31 therein unless it has some egress to the atmosphere. Such an exit is provided by a duct 66 joined to the piston 31 and extended to a discharge nozzle 67 mounted on a bracket 68 secured to the downstream edge 41 of the discharge bell. A movable nozzle needle 69 disposed within the nozzle has a stem 71 passing through appropriate packing 72 into a housing 73 upstanding from the outer shell 18. A control rod 74 rises from the housing 73 to a hand valve '76 at an appropriate location, for example on the lioor 77 of a power house or ilow control station.

When the nozzle needle liquid which enters the pipe 62 free to dischargevto the atmosphere through the housing 67 so that no substantial pressure builds up within the chamber 26. When the nozzle needle 69 is closed, there is no escape from the chamber 26 and pressure fluid from the transition section 9 flows into the chamber 26, thus moving the piston 31 toward closed position. The arrangement constitutes a hydraulic jack to translate the discharge bell axially toward the right causing the seat 57 to approach and eventually to abut the seat 58 in its path. trated in Figure 2.

Since the interior surface of the discharge bell upstream of the seat 57 and the surface of the bafile upstream of the seat 58 are spaced apart, there is in effect 69 is in open position, any

a chamber 78 defined between them 1n communication with the interior of the conduit 16. This chamber has a substantial projected area perpendicular to the axis of motion and subject to the pressure of the contained liquid. This pressure urges the discharge bell toward open position, and is resisted only by the pressure within the chamber 26. Consequently, when the valve 64 is throttled and the nozzle needle 69 is open so that ow into the chamber 26 is less than flow out of it, then the chamber 26 in effect discharges or can be discharged under a superior force. That superior force results from the pressure of the contained liquid against the projected area of the chamber 78 and the interior of the discharge bell. Due to resistance to hydraulic flow, the pressure of the liquid within the mechanism is greater than the atmospheric pressure outside of it.

The effect of the interior pressure upon the surface band within the discharge bell between the seat 57 and the lining 36 is sufficient to overcome resistance to outflow of liquid from the chamber 26 when the nozzle is open. The discharge bell is therefore translated to the left from closed position toward and into open position. When the discharge valve opens there is some pressure drop from the presusre existing under closed conditions, but there is still sufficient pressure remaining to complete the motion of the mechanism.

By appropriately regulating the valve 64 to a set value and then by opening the nozzle needle 69 to an extent greater than that or to an extent less than that, the discharge bell can be moved to and fro to regulate the degree of opening of the structure. Actually, the arthe transition section 9 is provided o and the chamber 26 1s The valve in its closed position is illusrangement is such that an automatic regulation takes place. For example, if the discharge bell is too far open for the setting established by the hand wheel 76, the pressure tending to open the discharge bell is overcome by the continued increase of pressure fluid within the chamber 26 which enters through the valve 64 faster than it can escape through nozzle body 67.

Due to the increased pressure in the chamber 26, the discharge bell translates toward the right in Figure l. This not onlycloses the opening between the baffle and the discharge bell but simultaneously moves the casing 67 to the right and farther away from the nozzle needle 69, thereby affording a greater opening for the discharge of liquid at that point. The augmented discharge of liquid reduces the pressure within the chamber 26 and permits the pressure acting upon the discharge bell adjacent to the seat S7 to urge the discharge bell toward open position again. The system can hunt in the described directions but in the usual instance there is sufcient frictional drag in all of the mechanisms so that a desired, substantially stable position between the extremes is achieved by the discharge bell acting as valve and in response to a selected position set up by the hand wheel 76.

In the event of failure of the mechanism; that is, in the event an emergency condition arises, it is merely necessary to close the hand valve 64 whereupon the pressure of the water within the pipe 6 and within the conduit 16 is effective to translate the discharge bell into its fully open position, thus affording a free discharge of the contained liquid. Because of the location of the streamlined baille within the interior of the discharge bell and because of the careful contour of the interior of the bell and the exterior of the battle, the stream discharging from the valve is a shell annular in cross section or is a hollow stream with an air core so that the discharged Water stream tends to disrupt and not to flow for any great distance.

What is claimed is:

l. A free discharge valve comprising a conduit having an open end and a cylindrical outer wall, a flange extending from said conduit, a shell supported on said ange and having a cylindrical inner wall overlying said outer wall to leave an annular chamber therebetween, an annular piston slidable on said walls and reciprocable in said chamber, a discharge bell extending from said piston and reciprocable therewith, a baille spanning the open end of said conduit, a spider supporting said baffle on said conduit at a distance from the end thereof to leave an annular space therebetween, a rst seat on said baffle in the path of said bell, a second seat on said bell adapted to abut said rst seat during reciprocation of said bell, a pipe for conducting actuating uid from said conduit to said chamber, a duct on and movable with said bell for conducting actuating fluid out of said chamber, a control valve in said duct, and means connected to a stationary part of said free discharge valve for operating said control valve.

2. A free discharge valve having all parts disposed upstream of the lip of a discharge bell comprising a con duit having an open end and a cylindrical outer wall, a flange extending from said conduit, a shell supported on a foundation and coupled to said flange and having a cylindrical inner wall overlying said outer wall to leave an annular chamber therebetween, an annular piston slidable on said walls and reciprocable in said chamber in a predetermined axial direction, a discharge bell extending from said piston and reciprocable therewith, a battle spanning the open end of said conduit, a spider supporting said baflle on said conduit at an axial distance from the end thereof to leave an annular space therebetween, mutually abutting valve seats on said baille and on said bell, said bell having an axially extended portion overlying said baffle in all reciprocated positions of said bell, rails on the exterior of said extended portion of said bell, said rails extending in said predetermined axial direction, and means on said foundation beyond the end of said baille for engaging said rails for supporting said bell during reciprocation thereof.

3. A free discharge valve having all parts disposed upstream of the lip of a discharge bell comprising a conduit having an open end, a baffle of larger diameter than said conduit mounted on said conduit at a distance from and spanning said end, a discharge bell having one portion encompassing and slidable on the outside of said conduit 6 and flaring into another portion of greater diameter than axially slidable on said walls in said chamber, a discharge said battle and extending axially beyond said bali'le in all el joined to and extending from said piston, said disslidable positions of said discharge bell means for sliding charge bell having one portion slidable on said inner said discharge bell on said conduit into and out of abutwall and flaring into a second portion terminating in a ment with said balle, rails on the exterior of the portion 5 substantially cylindrical lip and extending axially to overof said discharge bell of greater diameter, said rails in lie said ba e in all positions of said discharge bell a all positions of said discharge bell being axially beyond pipe for conducting actuating fluid from said conduit said baffle, and Wheels in a lixed position relative to said into said chamber, a duct opening through said piston conduit and axially beyond said baffle for engaging said and extending from said chamber to the atmosphere, a rails to assist in supporting said discharge bell in all 10 control valve in said duct, and means responsive to the positions thereof. axial position of said discharge bell for operating said 4. A free discharge valve comprising an axially excontrol valve. tending conduit having an open end and a cylindrical 4 outer wall, a flange extending 1flrom said cclincuit, a shell References Cited 1n the le of this patent supported on said flange and aving a cy in rical inner 15 wall overlying said outer wall to leave an annular cham- UNITED STATES PATENTS ber therebetween, a baille axially spaced from and span- 1,597,371 Gfeller Aug. 24, 1926 ning the open end of said conduit, said baffle terminating 2,010,416 Schlagenhaulf Aug. 6, 1935 in a diameter greater than that of said open end, a spider 2,416,787 White Mar. 4, 1947 supporting said balle on said conduit, an annular piston 20 

